Apple Mail.app and MobileMe Junk Filter need a lot of work. On daily basis, I mark too many of obviously junk mail on Mail.app and MobileMe such as the ones from bluesquareframe.com and LOL messaging. Gmail and and Yahoo! Mail junk filter work a lot better than the one Mail.app and MobileMe service have.
I saw this in my Mail.app:
An email from an Apple Store with a sales receipt was automatically marked as Junk by Mail.app. That is so ironic.
Apple needs to improve the Junk Mail Filter for MobileMe service. There are enough complaints from users that their MobileMe mail does not filter junk mail as it should. Apparently marking those mail as junk does not seem to improve the junk mail filter algorithm.